KBK update for Tuesday, 22nd October

Back in August 2018 I proposed an explanation for the origin of M1 (or M11): that it was created by Cherry for HP as a drop-in replacement for Datanetics DC-60 switches, based on a comment by Findecanor in 2014 followed by a comparison of dates and specifications.

After UncleFan came across the internals of a Cherry-made HP 9835 keyboard with M1 switches and a customer part number almost identical to that of the M1 space bar switch, I spent some time investigating, and discovered that the customer part number (Kundennummer or Kd.Nr) in the M11-0101 drawing is actually the HP part number assigned to the Datanetics DC-60 switch used for space bar on the HP 9825 computer, i.e. HP assigned an existing part number (for the switch to be copied) to Cherry when commissioning its replacement. HP for the most part pretended that they made all the switches and keycaps, so there are no Cherry or Datanetics part numbers up for grabs, but the DC-60 switch and Datanetics-made keyboard are clearly illustrated.

For the most part, in that the HP 85 service manual distinguishes between the Hi-Tek and Stackpole switches: Hi-Tek has one solid contact and one fingered contact surrounded by a white plunger, while the Stackpole switches use yellow plungers and a single contact type. This confirms for one that HP did buy from both companies, as believed.

View within the updates for 2019

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